In the field of meteorology one of the most persistent and vexing problems has been the lack of a static pressure probe configuration that is omni-directional relative to horizontal wind flows, as well as being relatively immune to static pressure errors induced by angle-of-attack variations that deviate from the horizontal particularly in environments contaminated by dust, snow and rain.
Significant vertical wind components occur with flows deflected from obstacles, also with turbulence and a variety of organized instabilities in the atmospheric boundary layer. Variable vertical wind components produce flows at an angle-of-attack different from that anticipated from typical local horizontal fields. Such angle-of-attack initiated dynamic pressure changes can cause significant errors in pressure measurements. In addition, atmospheric applications involve a requirement that the static pressure response of sensors should be independent of horizontal wind direction, unidirectional static pressure probes not proving useful.
Some of the prior art constructions that have been employed to provide a solution to this problem have involved the following structural arrangements: a single disk mounted flush with the top of a hollow static pressure stem wherein the stem is disposed in either a perpendicular or parallel orientation relative to the disk; and, porous or sintered material caps placed on the open end of a static pressure stem.
In addition, much research has been devoted to dual disk static pressure probe configurations as evidenced by the following articles: "An Omni-Directional Static Pressure Probe" by Richard W. Miksad; Journal of Applied Meteorology Vol. 15, Number 11 (November 1976 pages 1215 thru 1225; and, "Development and Testing of a No Moving Parts Static Pressure Inlet For Use On Ocean Buoys" by Gerald C. Gill in a paper published by the University of Michigan in August 1976.
In addition, to these scholarly dissertations the prior art is replete with myriad and diverse patented air pressure and velocity measuring probe configurations, as evidenced by the following U.S. Pat. No's: 4,056,001,3,956,932; 3,055,216; 3,520,184; 4,304,137; 4,559,835; 3,950,995; and, 3,686,937.
Despite all of the time, money, and research that has been devoted to providing a solution to this problem, to date no one has developed a workable omni-directional static pressure probe that is relatively immune to angle-of-attack variations. As a consequence, meteorologists have experienced a longstanding deficiency in their ability to monitor static pressure changes at remote tracking stations, which has hampered their ability in accurately forecasting sudden and dramatic weather changes.
With the current state of the art static pressure probes, too many variables inherent in both the construction and configuration of the probes per se, have produced static pressure errors of the magnitude that simply defy accurate prognostications based on the potential differences between the actual static pressure at the probe location and the static pressure that is being recorded by the probe instrumentation.
However, the quad disk static pressure probe apparatus that forms the basis of the present invention is believed to be the most accurate device that has been developed to date, particularly with regard to meteorologically acceptable static pressure error differentials at angle-of-attack deviations within the range of .+-.30.degree. from horizontal.